Seats for cars and light trucks have been formed by molding a foam bun that will serve as the seat cushion, and then attaching a pre-stitched fabric cover to the foam bun. Often, when the fabric cover is to be held securely to the foam bun along a bun contour, discrete retainers such as hog rings are employed to connect a fabric flange, extending from the inner surface of the cover, to a wire retained at the bottom of a corresponding trench in the foam bun surface. Tension in the cover flange holds the cover against the bun in the contour. Other fastening methods involve fastening a clip, secured in the trench, to a bead along the flange edge.
Some fastening methods can be very labor-intensive, and can require significant manual dexterity. Some also require pneumatic tools for repetitive installations, due to the force required.
Improvements in the methods of attaching covers to contoured foam products are sought, either for contoured foam seat cushions or other applications.